Method and apparatus for display of video images in a video conferencing system

Abstract: A method of displaying a video image in a computer which has the ability to simultaneously display multiple windows. A graphics image is displayed in a first window, and a video image is displayed in a second window having controls for annotating the graphics image in the first window.

Description: The present invention relates to a system in which both graphics and video images are transferred between users of remotely located computers. More, particularly, it relates to the relationship between the graphics and video images and how these images are displayed. Collaborative computing involves the generation of data such as a graphical image by an application running on one of the computers and the replication of that image on the displays of the other computers. The system also involves the control of the common image including the ability of different users to change and/or annotate the image. Another feature of this collaborative computing system is the generation of a video image of a user of one of the computers and the transfer and display of that image at remote locations. The present collaborative computing system involves the interrelationship of the graphics and video images transferred between computers. IEEE INFOCOM '91 THE CONFERENCE ON COMPUTER COMMUNICATIONS, vol.3, 7 April 1991, BAL HARBOUR, FL, USA pages 1127-1144 TANIGAWA ET AL. 'PERSONAL MULTIMEDIA-MULTIPOINT TELECONFERENCING SYSTEM' discloses a personal multimedia-multipoint teleconference system which allows conferences using voice, video and graphics to be established using a broad band ISDN. NTT REVIEW, vol.4, no.4, July 1992, TOKYO, JP pages 81 - 85 MASAKI ET AL. 'A DESKTOP TELECONFERNCING TERMINAL BASED ON B-ISDN : PMTC' discloses a multimedia teleconference system with a multiwindow display having text graphics, telewriting, telepointing and high quality full motion video and voice facilities. IEEE TRANSACTIONS ON COMMUNICATIONS, vol.39, no. 11, November 1991, NEW YORK, US pages 1698 - 1708 ROBINSON ET AL. 'A MULTIMEDIA INTERACTIVE CONFERENCING APPLICATION FOR PERSONAL WORKSTATIONS' discloses a multimedia interactive conferencing application for personal computers for multipoint visual teleconferencing which allows users to interactively share visual material such as documents, photographs and screens and supports the distribution, storage and retrieval of visuals and real-time interaction by pointing and annotation. It is an object of the present invention to provide a method of and a system for displaying and controlling both graphics and video images on a computer display. According to a first aspect of the present invention there is provided a method of displaying a video image in a computer having the ability to simultaneously display multiple windows, the method comprising the steps: a) displaying a graphics image in a first window; b) displaying a video image in a second window; and characterized by the steps of c) displaying in a third window control elements for annotating said graphics image in said first window; and d) when said graphics image is displayed, automatically transferring said video image from said second window into said third window and closing said second window. According to a second aspect of the present invention there is provided a computer system comprising one or more computers, each having the ability to simultaneously display multiple windows, comprising: means for displaying a graphics image in a first window; means for displaying a video image within a second window; characterized by means for displaying in a third window control elements for annotating said graphics image in said first window; and means for automatically transferring said video image from the second window into the third window when said graphics image is displayed and for closing said second window. An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:- Figure 1 is a view of a manager window on a computer display screen, Figure 2 is a diagram showing changes in views of two different computer display screens in accordance with one embodiment of the present invention; Figure 3 is a view of the manager window of Figure 1 with a video image added; and Figure 4 is a diagram showing different views of a computer display screen in accordance with another embodiment of the present invention. An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:- The phrase "graphics image" as used herein refers to an image generated by a computer program. It is generally time independent, meaning that any changes that are made in the image can occur at irregular intervals without significantly degrading its performance. For example, graphics images include alphanumeric characters as generated by a word processing application, graphical data as generated by a spread sheet application, drawings as generated by a paint or design program, etc. The phrase "video image" as used herein refers to a time dependent image generated by a motion picture camera. It is time dependent because the image must be continually updated at regular intervals in order for any motion in the image to be perceived by a viewer as smooth. The term "window" as used herein means a region (usually rectangular) of a computer display screen which the operating system of the computer grants use of to an application. The window has associated controls which direct the actions of the application. The size and location of the window on the display screen can also be changed by the user of the computer. A computer having the ability to display multiple windows provides visual access to the application running in each of the windows. Typically, the user of the computer can scale, move and otherwise arrange the windows on the screen. Figure 1 is a view of a manager window 10 as displayed on a computer display screen 12 associated with a computer. The computer (which is not shown) is equipped with a video camera. The camera may be mounted on an edge surface of the display screen and will be pointed in the direction of the user of the computer. Manager window 10 controls the main functions associated with a video conferencing system. This video conferencing system provides video images of the participants and allows sharing of documents. The communications are provided over telephone lines having ISDN (Integrated Systems Digital Network) capabilities. Manager window 10 includes a title region 14, a control region 16, and an annotation region 18. Control region 16 includes various control elements (selectively marked as 20a, 20b, ...). Control elements 20 may be selected and activated with a pointing device, such as a mouse or through a keyboard. Control elements 20 perform a number of functions related to the establishment and control of a communications link with a remotely located computer. (The remotely located computer will be similarly configured with a video camera.) For example, the control element 20a labeled "Video" allows the user of the computer to make a video call to a remotely located computer. The Video control element 20a has other functions - one of which will be discussed in more detail later. Another control element 20b, labeled "Share," allows the user of the computer to establish a video conference call with a participant at a remotely located computer. As will be discussed in more detail below, the Share control element 20b allows the user of the computer to share both a video image and a graphics image with a remote participant. Figure 2 is a diagram showing changes in views of two different computer display screens according to one embodiment of the present invention. Starting with the selection of Share control element 20b by the user of the computer, hereinafter referred to as the local computer, the successive views on local computer display screen 12a and remote computer display screen 12b are shown. The successive views of local computer display screen 12a are shown by local branch 22. In a first view 12a-1 of the computer display screen, "only" the manager window 10a, as described with respect to Figure 1, is active. As with all of the views of the computer screens described herein, there may be other windows displayed on the screen, as is commonly known in the art. With respect to the subject invention, several windows associated with various parts of a video conferencing system may be generated. These windows will be collectively referred to herein as "video conferencing windows." These video conferencing windows are shown in Figure 2 and will be described shortly. The statement that "only" manager window 10a is active in first view 12a-1, means that manager window 10a is the only video conferencing window that is active on the screen. However, other non-video conferencing windows may be displayed, at the option of the user of the computer. Referring again to first view 12a-1, manager window 10a is displayed. As shown in more detail in Figure 1, manager window 10 has a control element 20b which allows the local user to establish a video conferencing session. As the session is being established, a video window 26 is generated, and a video image taken by the video camera on the local computer is displayed therein, as shown in the second view 12a-2. The local video image, i.e., the image of the user of the local computer, which is displayed in video window 26 is labeled as "Local." When the communications link is established, the user of the remote computer (path 24) has the option of accepting or rejecting the call. If the call is accepted or answered and the video camera on the remote computer is active, the video image from the remote computer is transferred to the local computer and displayed in video window 26, as shown in the third view 12a-3. It is expected that the remote video image will be the image of the user of the remote computer. This image automatically replaces the local video image. The term "automatically" as used herein means without user intervention. The local user also has the option of sharing a graphics image. In this regard, the phrase "video conferencing" to describe the subject system broadly encompasses both the video images being exchanged between the local and remote computers, as well as the sharing of graphics images generated by a computer program resident on only one of the computers. If the local user starts a program to generate a graphics image to be shared with the remote computer, the associated graphics image of the application is displayed in an application window 28, as shown in fourth view 12a-4. When the graphics image is displayed, the video image is automatically transferred from the video window 26 into the manager window 10a, and the video window 26 closed. Figure 3 is a more detailed view of the manager window 10a in Figure 2. It may be helpful to compare manager window 10a in Figure 3 with the manager window 10 in Figure 1. The windows are similar with the exception that manager window 10a is somewhat larger than window 10 in order to accommodate the video image. By displaying the video image within the manager window 10a, the user is provided with a significant advantage in using the video conferencing system. The video image remains visible to the user during a conferencing session. Furthermore, the various controls and annotation tools (to be described later) are also readily available. The user can position the manager window at any location on the screen that is convenient. However, at the same time, the user does not have to contend with positioning the video window - the video image being part of the manager window. Figure 2 also shows a series of computer screen views on the remote computer shown by path 24. In a first view 12b-1, a window 30 indicating an incoming call "pops up" on the screen of the remote user. Control elements in window 30 allow the remote user to reject or accept the incoming call. If the call is accepted, a second view 12b-2 is generated in which a video window 32 is displayed on the screen. Initially, video window 32 displays an image of the user of the remote computer (labeled "local"). The terms "local" and "remote" as used herein to describe the origin of video images are with respect to the user of the specific computer. In other words, the term "local" when used in the views of path 22 refers to the user of the local computer. In contrast, the term "local" when used in the views of path 24 refers to the user of the remote computer. After the call is answered, the video image from the camera associated with computer screen 12a is transferred to the remote computer. This video image is then displayed in video window 32, as shown in the third view 12b-3. This image automatically replaces the video image shown in view 12b-2. When the local user starts a program, as discussed above, to generate a graphics image to be shared with the remote computer, the associated graphics image of the application is transferred to the remote computer. The graphics image is then displayed in an application window 34, as shown in fourth view 12b-4. Because the remote user has not opened a manager window, both the video and application window are displayed. (The manager window for the remote computer must be active - however, it is not necessary that it be displayed.) In order to participate in a video conferencing session, both the remote and local computers must run video conferencing software. Such software includes the manager window and functions, described above. Thus, the remote user has the option of opening a manager window 36 in the remote computer, as shown in the fifth view 12b-5. When manager window 36 is opened, the video image is automatically transferred from the video window 34 into the manager window 36, and the video window 32 closed. Another feature of the present invention is shown in Figure 4 in the two different views 12c-1 and 12c-2 of a computer screen. View 12c-1 is similar to that shown in views 12a-4 and 12b-5 in Figure 2. Namely, two windows - an application window 40 with a graphics image, and a manager window 42 including a video image are displayed. View 12c-2 shows three windows - application window 40, manager window 42 and a video window 44. In view 12c-2, the video image has been moved from the manager window 42 into its own video window. This move occurs in response to a command from the user of the computer. In practice, this transfer can be completed either by activating a control (such as Video control element 20a) in manager window 42 or by establishing a fast transfer command, such as using a mouse to point at the video image and double clicking. Similarly, the video image in view 12c-2 can be moved back into the manager window 42 by a predetermined control in either the video or manager window. Another feature of the video conferencing system can be seen by referring back to Figure 1. More particularly, reference is made to annotation region 18. Region 18 includes a number of controls or tools for annotating a graphics image, such as shown in application windows 28 or 34 in Figure 2, or for annotating a video image, such as shown in video windows 26 or 32 in Figure 2. Some of the tools provide the capability of generating straight, curved or freehand lines and text; the ability to selectively or universally erasing the annotations; and a palette for changing the colors of the annotations. Each of these tools has the ability to change the appearance of the image in another window. The term "annotating" when used herein with respect to a graphics or video image means to add a second image over the graphics or video image. In the case of a graphics image, the second image is generated by a different program than generates the graphics image. For example, underlining and overstriking which may be available within a word processing program are not considered "annotating" within this definition. However, underlining, highlighting, commenting, etc., are annotations if they are provided by a separate program. Such annotations are displayed by logically combining the annotations with the graphics images in the video display memory. This Table describes a specific embodiment of the invention which uses the following terms and phrases: "TeleGraphics" is a trade name used to describe the overall collaborative video conferencing system described in the subject case and those cross-referenced herein. "TeleMedia Manager" is a trade name used to describe a specific implementation of manager window 10. "Annotation toolbar" refers to annotation region 18. anntb.c Functions to display the annotation toolbar (the bottom half of the TeleMedia Manager screen) anntb.h Data structures and prototypes needed to display the annotation toolbar annvid.c Functions to display video when it is inserted in the annotation toolbar annvid.h Data structures and prototypes needed by annvid.c televid.c Functions to display the portion of the annotation toolbar that appears under the video portion of the toolbar televid.h Data structures (named identifiers) and function prototypes needed by televid.c tmscreen.c Functions to support the TeleMedia Manager screen and controls (e.g. the buttons). The functions handle the buttons, the changing of the button states, etc. umb.c Functions to display the main portion of the TeleMedia Manager screen Contains the main program for the TeleMedia Connection and its window procedure umb.h Named identifiers and function prototypes needed by umb.c vidwin.c Functions to interface with the video device driver vidwin.h Prototypes and data structures needed to interface with the video device driver

Claims: A method of displaying a video image in a computer having the ability to simultaneously display multiple windows, the method comprising the steps of: a) displaying a graphics image in a first window (28); and b) displaying a video image in a second window (26,44), characterized by the steps of c) displaying in a third window (10a) control elements for annotating said graphics image in said first window (28); and d) when said graphics image is displayed, automatically transferring said video image from said second window (26,44) into said third window (10a) and closing said second window (26,44). A method according to claim 1, characterized in that said video image is transferred to said computer from a remotely located computer. A method according to claims 1 or 2, characterized in that said graphics image is transferred to said computer from a remotely located computer. A method according to claim 1, characterized by the further step of: activating a control element (20) in said third window (10a) to recreate the second window (26,44) and move said video image from said third window (10a) to said second window (26,44). A computer system comprising one or more computers, each having the ability to simultaneously display multiple windows, comprising: a) means for displaying a graphics image in a first window (28); b) means for displaying a video image within a second window (26,44); characterized by c) means for displaying in a third window (10a) control elements for annotating said graphics image in said first window (28) ; and d) means for automatically transferring said video image from the second window (26,44) into the third window (10a) when said graphics image is displayed and for closing said second window (26,44). A computer system according to claim 5, characterized by two or more computers, each of the computers having a single window in which a common application is shared, comprising means for displaying multiple windows in a first of said computers, comprising: means for displaying said shared window; means for displaying a manager window having tools for changing the appearance of the application in the shared window; and means for displaying a video image received from a second of said computers in said manager window.

Inventors: CARLETON ALLISON A, PETERSON PAUL A, SCHWARTZ WILLIAM C, CARLETON, ALLISON A., PETERSON, PAUL A., SCHWARTZ, WILLIAM C.
Applicants: NCR INT INC, NCR INTERNATIONAL, INC.
Application year: 1994
Main classification: H04N7
IPC codes: G06F15, G06F3, H04N7